An extension to the NHLBI Growth and Health Study (NGHS I, HC-55025), a five-year cohort study of the development of obesity and its effects on cardiovascular disease (CVD) risk factors in black and white adolescent females, is proposed to continue tracking the cohort until subjects complete pubertal maturation. the extension is proposed because during NGHS I, when the subjects were ages 9-10 to 13-14 years, race differences in pubertal (physiological) and adolescent (psychological-behavioral) factors observed in the subjects were confounded. During these ages in NGHS I, black girls were more mature at every annual visit. During NGHS I, black girls also had greater between-visit changes (increases) in dietary intake, height, weight, adiposity, and blood pressure. They were taller and heavier at every visit within age strata. Because sexual maturation is itself associated with greater height, weight, and adiposity, behavioral and cultural factors contributing to race differences in weight gain are confounded with maturational differences and identification of behavioral factors is limited. Race differences in anthropometry for girls at baseline, however, were not significant, except for triceps skinfold for which whites were larger. Consequently, NGHS II will follow this cohort of girls until they have completed pubertal maturation. Specifically, NGHS II will measure: 1) antecedent factors believed associated with obesity (food attitudes and patterns, diet, physical activity and exercise patterns, and attitudes towards obesity, and thinness); 2) body habitus (height, weight, adiposity, circumferences and maturation); and 3) CVD risk factor levels (total, HDL and LDL cholesterol, triglycerides, blood pressure, and smoking). We will conduct these studies on the same girls and their parents with whom we have been working successfully for the past 4 1/2 years in NGHS I, following them for three (3) more years until all girls have completed puberty. Thus, NGHS II will provide unique insights in factors associated with the differential increase in weight and adiposity in adolescent females and potentially identify practical interventions.